function disableSelection(target){
 if (typeof target.onselectstart!="undefined") //IE route
  target.onselectstart=function(){return false}
 else if (typeof target.style.MozUserSelect!="undefined") //Firefox route
  target.style.MozUserSelect="none"
 else //All other route (ie: Opera)
  target.onmousedown=function(){return false}
 target.style.cursor = "default"
}
disableSelection(document.body);